Efficacy of Selected Conventional and Experimental Insecticides for Control of European Corn Borer on Snap Beans, 1997

Abstract

Abstract Trials were arranged in a RCB design with four replications. Each replicate had a plot consisting of four 30-inch-wide, 20-ft-long rows. Twenty-five-foot-wide alleys were established between each of the four replications. Insecticides were applied to the middle two rows of each plot, leaving two untreated rows between each plot. Eight insecticide treatments were compared with two untreated checks after multiple manual infestations of ECB egg masses. The two untreated check plots were averaged for the ANOVA. Treatments were to be applied at 28, 21, 14, and 7 days before harvest (DBH); however, because of slow plant development, applications were made at 33, 27, 20, and 12 DBH, every six to eight days beginning on 31 Jul. All insecticide treatments were applied with a modified John Deere 6000 high-clearance vehicle (HCV) with a rear-mounted boom. Six Conejet (TX VS-6) hollow cone nozzles (three per row) were calibrated to deliver 25.2 gpa at 40 psi and a speed of 2.5 mph, utilizing a compressed air system. Four nozzles (2 per row) were attached to drops and directed toward the under surface of the snap bean canopy, area, a third nozzle (one per row) was mounted directly over the row. In one of the center two rows of the 4-row plot, a seven-foot section of row was marked and manually infested (by pinning) with black-headed stage ECB egg masses on wax paper disc, to the foliage of the snap bean plants. Four eggs masses per foot of row were attached i on the following dates: 25 Jul, 1, 8, 15, and 22 Aug.